In situ measurement of cake thickness distribution by a photointerrupt sensor
Journal
Journal of Membrane Science
Journal Volume
190
Journal Issue
1
Pages
57-67
Date Issued
2001
Author(s)
Abstract
An in situ optical method was developed to determine the thickness of the cake layer by using a low-cost photointerrupt sensor. The effects of slurry concentration, agitating speed (i.e. slurry transport velocity), background light and color of slurry on the accuracy of measurement were examined to verify the validity of this method. The accuracy of the thickness measurements was confirmed using uniform sized PMMA spheres. Experimental results show that the developed technique is useful for cake thickness ranging from 10£gm to 5mm and yields a vertical resolution as high as 10£gm in the same order as that of gamma-ray absorption and NMR micro-imaging methods. This method has benefits of inexpensive, easy installation and a comparable accuracy compared with gamma-ray absorption, NMR micro-imaging and CATSCAN techniques. The developed method was then applied to measure the time course of cake layer thickness variation on the membrane surface during cross-flow micro-filtration of a PMMA suspension. Results of measurements show that the dynamic surface shape is not at all flat during a course of CFMF. Copyright ? 2001 Elsevier Science B.V.
Subjects
Cake thickness distribution
Cake thickness measurement
Filtration
In situ measurement
Photointerrupt sensor
Type
journal article